This application is related to Japanese Patent Application No. 2000-374291 filed on Dec. 8, 2000, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a case connection structure for integrally connecting plural division case members. The case connection structure is suitably used for a case of vehicle air conditioner.
2. Description of Related Art
In a conventional vehicle air conditioner, plural division case members are separately formed by resin, and are integrally connected for constructing a case of a cooler unit, a heater unit or a blower unit. However, because air-conditioning components are disposed within the division case members, the connection operation becomes difficult. For example, for accommodating an air mixing door, a heater core and mode switching doors in the heater unit case (the case of the heater unit), an assembling operation of the heater unit case is divided into a first assembling step and a second assembling step, and the first assembling step and the second assembling step are independently performed using suitable methods and equipments, respectively. When the heater unit case is divided into both upper and lower division case members for accommodating the air-conditioning components, it is necessary to temporally assemble both the division case members in the first assembling step by using screw members after the components are accommodated in the division case members. When both the division case members are not temporally connected in the first assembling step, a connection between both the division case members is removed while the temporally assembled body is moved to a place where the second assembling step is performed, and a regular assembling position of the air-conditioning components may be shifted.
In view of the foregoing problems, it is an object of the present invention to provide a case connection structure in which an assembling state between both division case members can be held without a fastening operation such as a screw fastening connection and a spring clip connection.
According to the present invention, in a case connection structure for connecting a first case member having a first connection end portion and a second case member having a second connection end portion corresponding to the first connection end portion of the first case member in a connection direction, a boss portion is provided to protrude from one of the first and second connection end portions toward the other one of first and second connection end portions in the connection direction, and a recess portion is provided in the other one of the first and second connection end portions. By fitting the boss portion into the recess portion, a fixing position of both the connection end portions of the first and second case members can be performed. In the case connection structure, a press-fitting portion is provided in the recess portion, and a slit is provided in the boss portion. When both the first and second case members are connected in the connection direction, the boss portion is fitted into the recess portion, and the press-fitting portion is press-fitted into the slit to press-expand the boss portion to an outer side, in such a manner that an outer wall surface of the boss portion press-contacts an inner wall surface of the recess portion. Accordingly, a friction force is applied between an outer wall surface of the boss portion and the inner wall surface of the recess portion, and an assembling state between both the first and second division case members can be held without performing a fastening operation such as a screw fastening connection or a spring clip connection.
Preferably, the press-fitting portion has a taper portion for increasing a press-expanding amount of the boss portion to the outer side, and the press-fitting portion is tapered toward the boss portion. Therefore, even when the dimension difference of the boss portion is caused in a manufacturing step, the outer surface of the boss portion can accurately press-contact the inner wall surface of the recess portion. Accordingly, a sufficient friction force can be obtained between the outer wall surface of the boss portion and the inner wall surface of the recess portion, even when the dimension difference of the boss portion or the recess portion is caused in the case members.